Operating Temperature

If she got into the 250 range as you said, you may have blown a head or intake gasket :blue:
You are on the right track with the test you stated. Good luck!!

 

Intake gasket? I thought each of the 4 throttle bodies were connected via rubber boots?

 

You would be correct. I wrench more cars than bikes and have had intake gaskets cause white smoke. How long was she in the 250+ range?

 

Under a minute. Light came on, I jumped on immediately (opposite of ATGATT) and rode low RPM low Load to get some airflow until it was down around 215 and I shut it off.

 

hmmmm, any water in the oil?

 

Oil looks normal in the sight glass and no milky residue on the bottom of the fill cap. Coolant also looks and smells clean...

 

Pumped up the cooling system to 16psi...holding pressure initially...will report back in 5-10 minutes time...

EDITS:
10 minute mark holding 16psi
20 minutes 16psi
30 minutes 16psi
40 minutes 16psi
Feeling cautiously optimistic right now. Still wanna pull the spark plugs and see what story they tell. Definitely gonna compression test her also.

Could it have just been the dead fan causing it to overheat and create an air pocket?

New fan showed up today, got a new thermostat and coolant so I'll make a day of that and see what happens...

 

Fan upgrade

What did you do for the fan upgrade? My 02' 800 runs way to hot, put a manual stitch on it to turn on sooner, and it did not help, fan works but is weak, any higher CFM fans out there?

 

Most newer engines run consistently at 210 degrees., like they have a 210 degree thermostat. It's pretty well understood that higher coolant temps lead to lower cylinder wear rates. The key is that 210 degrees is only the average temp and other areas of the system can greatly exceed that. Cooling system chemistry and flow become much more critical at higher temperatures but modern engineering allows that.

For further explanation, lower liner temps lead to cylinder glazing which leads to poor lube retention and accelerated liner wear. On larger engines exhaust gasses can cause corrosion on cooler liners.

 

What I am reading leads me to believe that I don't have much to worry about.

It is Normal for a 5th Gen to run 200+ in town?

The "New to me" VFR runs in the 180 range on the highway. But last evening I saw 205 sitting at a traffic light. I did not hear the cooling fan come on.

I'll be doing a fairly comprehensive maintenance bit on the bike in a few weeks, but in the meantime I want to make sure I don't fry anything....

 

That's totally fine.

 

Yes. In 90°F weather I see 220 at stops.

If you don't know if the fan is working yet, idle it until 220 or so to make sure the fan is working.

 

Anything below 221 which is where the fan kicks in. It's that simple. In hot summers, the bike will run warmer than in the winter. That simple.

 

You're totally fine even to 230 degrees. Cars are safe up to 260 but bikes usually run less glycol 70/30 instead of 50/50 and they also have lower pressure radiator caps. They key is, you're fine until the coolant boils.

 

Reviving this thread because I had a hair-raising moment yesterday coming home from a 600 mile ride...

Riding through the Cross Bronx Expressway--err parking lot my coolant temps rose steadily with the fan on up to 254*.

The temps immediately started falling once we started lane splitting and I got some air through the radiators but the temps were rising so fast it was skipping numbers [244, 246, 249].

Is this normal for it to climb so high so fast? I cant imagine the bike is incapable of sitting in traffic for more than 6 minutes WITH THE FAN ON without blowing a head gasket...

 

Hi, today, returning home after a nice ride in sunny weather, standing in front of the garage, waiting for the door to open, engine idling, the temp of my bike reached 106 grades C which is the moment the fan usually starts working. I rode in the garaze and when turning the ignition off I spotted a trace of a liquid. I could hear bubbling and could see liquid flowing down the bike. I looked once more at the display and could see temperature 111 C. At the weekend I filled the overflow bottle up the higher line with the coolant (destilled water).

In some of the discussions here I could see that the fan doesn´t start if there is too much liquid in the cooling system. Could this be the case? When running the liquid was slightly above the maximum level. Then, at temperature above 100 degrees C the volume even increases and the coolant can spew out of the overflow bottle. Well, it has never ever happened to me so far. Even the temperature has always stopped at the level around 107 degrees C because of the working fan. I will have to test the fan whether it is working, but could just too much coolant be to blame?

 

If your bike is spewing coolant at 111, you need a new radiator cap. The cap is designed to hold 1.1 bar pressure and this increases the boiling point to 130C. If the pressure is not held, then it will boil at 107C and spew steam through the reservoir.

The fan operation is solely controlled by the thermoswitch, and has nothing to do with the coolant level (as long as the radiator is full). You can check the fan operation by pulling the wire off the spade terminal the at the switch and shorting the cable end to the frame/ground.

 

A new radiator cap is not expensive, and I second the recomend replacement.

 

That is what my 2014 does. So sounds normal.

 

I had aradiator cap gp bad on me and spewed coolant on the back tire. I went down in a heartbeat because of glycol being incredibly slippery on rubber. $9 to replace at AutoZone. Not Honda but it works very well and you don't get screwed by the stealership.